package leetcode;

public class ListNode203 {
    public int val;

    public ListNode203 next;

    public ListNode203(int x){
        val = x;
    }

    // 链表节点的构造函数
    // 使用arr为参数，创建一个链表，当前的ListNode为链表头结点
    public ListNode203(int[] arr){
        if(arr == null || arr.length == 0)
            throw new IllegalArgumentException("arr can not be empty");

        this.val = arr[0];
        ListNode203 cur = this;
        for(int i = 1; i < arr.length; i++){
            cur.next = new ListNode203(arr[i]);
            cur = cur.next;
        }
    }

    // 以当前节点为头结点的链表信息字符串
    @Override
    public String toString(){

        StringBuilder res = new StringBuilder();
        ListNode203 cur = this;
        while (cur != null){
            res.append(cur.val + "->");
            cur = cur.next;
        }
        res.append("NULL");
        return res.toString();
    }
}
